Chemical investigations are often carried out on a micro-volume scale within microtubes that are configured to hold, by way of example, 0.25 mL to 2 mL of volume. These tubes allow the investigator to test several combinations or reactions at a single time without large volumes or expense. The tubes may be capped and stored as arrays in racks of 16 to 96 tubes each. Conventionally, capping and decapping of tubes was accomplished individually by hand when the addition of reagents or withdrawal of the sample was necessary. Recently, multi-channel pipetters have allowed technicians to work simultaneously with multiple tubes at a time. Still, capping and decapping was accomplished manually.
More recently, table top capper and decapper devices have been designed that cap and decap the full two-dimensional array of tubes within a rack. However, these devices are large, bulky, costly, and operable only with respect to all caps from all tubes within the rack. Often, it is necessary to add reagents to only a subset of the tubes within the rack and/or to limit the samples exposure to air.
Accordingly, it would be of great benefit to provide a smaller, more cost effective manner of capping/decapping a subset of tubes within the rack.